It is an innocent looking semi-detached property in the university city of Cambridge from where an Islamic charity, dedicated to peace and interfaith friendship, operates.

The leaders of the Islamic Academy are so moderate that they were recently invited to share a platform with Rowan Williams, the Archbishop of Canterbury.

Yet there are growing suspicions that this suburban house is where the origins of the suspected London and Glasgow bomb plots may lie, The Sunday Telegraph can reveal.

The links between Bilal Abdullah, Kafeel Ahmed and others arrested in connection with the alleged plot came as shock to the unsuspecting congregation who gathered to pray at the Islamic Academy on Friday.

Security sources have confirmed to this newspaper their interest in the activities of several of the terror plot suspects in Cambridge. Sheikh Abdul Mabud, the Academy's chief executive, refused to discuss whether he had been contacted by police.

The academy's unwitting connection to these events may have begun in May 2004, with Kafeel Ahmed, 27, who is under police guard in hospital suffering from 90 per cent burns sustained in the botched Glasgow attack.

Between May 2004 and August 2005, as a PhD Student at Anglia Ruskin University in Cambridge, he rented a room above the academy's offices and prayer chamber.

In the room next door, it can be revealed, was another lodger: the Cambridge organiser for Hizb ut-Tahrir (HT), the radical Islamist movement which has caused such alarm that David Cameron, the Conservative leader, called on Wednesday for it to be banned.

Kafeel Ahmed would occasionally be visited by his brother Safeel, 26, a junior doctor who was last week arrested in Liverpool.

It is claimed, however, that a more frequent visitor to the house was Bilal Abdullah, 27, who was yesterday remanded in custody after being charged with conspiring to cause explosions. Three years ago, he is believed to have been living above a takeaway close to the academy.

The friendship, and possible radicalisation, in the house was witnessed by Shiraz Maher, a former HT member who claims that he and the group's leader would often meet with Kafeel Ahmed and Abdullah to discuss politics on the floor of the deserted, book-lined prayer room.

"The HT guys and Bilal controlled, steered and directed the conversation," Mr Maher alleged. "Kafeel listened more than he talked. He became more religious as he progressed.

"Everyone there contributed to Kafeel's radicalisation and he listened to all of us, but he and Bilal were very close. By the time I left Cambridge in July 2005, Kafeel and Bilal were probably best friends."

Mr Maher added that, with Mr Mabud often working away from his office at the academy, there was no need to disguise the radical opinions of the lodgers or their friends.

On Friday, those attending prayers at the academy, more than half of them in their twenties and many highly educated, insisted they could not remember any of the suspects.

Mr Mabud said that he remembered Sabeel Ahmed coming to visit his brother once or twice a year but insisted that he did not recognise the Kafeel Ahmed he knew in the photographs of the burned man at Glasgow Airport.

"The Kafeel Ahmed who lived here was a fine man, busy with his PhD, very polite," he said. "I would be very surprised if it turns out to be the man who was at Glasgow Airport."

Mr Mabud said that he had never seen Abdullah and did not remember the alleged HT leader. Explaining that he was the only person who regularly used the academy's offices, he added: "What more can we do? As human beings, you can only do so much."

A spokesman for HT said: "Our methodology is one of intellectual and political work and not militancy, violence or armed struggle. None of the suspects arrested were members of Hizb ut-Tahrir or had any affiliation whatsoever with Hizb ut-Tahrir."

Sejad Mekic, the imam at the Cambridge mosque which Abdullah also attended, gave a sermon on Friday condemning all acts of terror.

However, he later said he had doubts that the incident at Glasgow airport was a terrorist attack, saying it could have been a car accident.

"I still haven't made my conclusion," he said.

When it was pointed out that containers of petrol were reportedly found in the car, he said: "Maybe they used to sell petrol. "http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/07/08/nterr308.xml